The 43-year-old, who was seized in northern Syria, insists he writes the scripts for the videos himself and calls on the UK government to negotiate his release.
The lengthy piece was included in the fourth issue of IS' 'Dabiq' magazine and carries the headline: "The real story behind my videos."
Cantlie, who has worked for newspapers including 'The Sunday Times', has featured in a series of propaganda videos released by the Islamic extremists in recent weeks.
In the six-minute video, he is again wearing an orange jumpsuit and speaks clearly and slowly, apparently from a script.
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He described the reaction to the beheadings of fellow British hostages David Haines and Alan Henning as "win-win" for IS.
He said: "If these executions force public outcry or a policy change, that is a huge victory.
"And if they only goad our governments into dropping more bombs and spending millions more dollars, making our countries weaker in the process, that is a victory too.